ASSESSMENT OF GLIOMA RESPONSE TO 8 GY RADIOTHERAPY ON MULTIPLE MRI BIOMARKERS BY APPLYING IMAGE SEGMENTATION ALGORITHM

brain tumor;APT imaging;image segmentation;multiparametric MRI;response assessment;Biomedical Engineering

Yu, YangZhou, Jinyuan ;

Johns Hopkins University

关键词: brain tumor;    APT imaging;    image segmentation;    multiparametric MRI;    response assessment;    Biomedical Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/40659/YU-THESIS-2015.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Magnetic Resonance Imaging (MRI) is playing a significant role in assessment of treatment response for a variety of diseases. To investigate multi-parametric MRI biomarkers for the assessment of glioma response to radiotherapy, we made comparison among different MRI parameters. In the tumor extraction step, we compare the manual segmentation, automatic and semi-automatic methods based on region of interest (ROI) results. In our experiments, thirteen nude rats injected with U87 tumor were irradiated by 8 Gy radiation dose. All MRI were performed on a 4.7 T animal scanner at time points of pre-radiation, 1 day, 4 days and 8 days post-radiation. Multi-parametric MRI signals of the tumors were compared in quantitative. Two experts performed manual and semi-automatic methods on tumor extraction on Amide Proton Transfer-weighted (APTw) maps.The results shows that average Apparent Diffusion Coefficient (ADC) intensity of ROI had a great increase during the post-radiation. The relative blood flow values (tumor vs. normal contralateral side of brain) had a continuous decrease after radiotherapy. Similarly, APTw signals intensity decreased at all time after radiotherapy. Semi-automatic method gave a more stable ROI extraction result on APTw maps than manual segmentation without rater dependence, and with less time consumption. In conclusion, ADC, blood flow, APTw are all helpful signals in assessing glioma response to radiotherapy. Also, semi-automatic method on ROI extraction showed higher efficiency and stability than manual method.